This invention relates generally to electronic paper handling devices, namely paper handling mechanisms for printing devices, copying, scanning, facsimile sending and receiving devices, and more particularly to the mechanisms for feeding media stock into these devices.
Paper handling devices are part of a printer, devices for producing a recorded image, and can also be found in association with scanning devices for electronically or optically sensing a recorded image for later modification, facsimile devices for electronically sending or receiving an image over a voice frequency circuit, and copying devices for reproducing a recorded image. Paper handling has involved the use of a wide variety of cams, rollers, motors and guides which can take a significant amount of space in association with the above devices. The number of parts and size of this device relate to the cost to manufacture and cost to use the devices. There has been an interest in reducing the number of parts needed to accomplish the same task, so as to minimize repair bills, and the cost to manufacture the base device. Thus, effort has been spent to create a paper transport devices attachable to the above devices that can accomplish multiple tasks at a lower cost, requiring fewer parts and smaller space.
Typical printing devices, which utilize paper transport mechanisms, include dot matrix, ink and laser printers. Dot matrix printers generate characters on a page with a matrix of dots and the aid of an inked ribbon and use guides and motors for moving paper into the printer. The Apple Stylewriter Inkjet printer series, for example utilizes a motor to dive a carriage containing an ink cartridge back and forth along the width of a sheet of paper according to electronically received information, such as from a computer. The paper is moved into the machine in one direction, then out the other side. The device requires paper guides in two places, taking up additional height in the device. There is no bi-directional option, which would enable the paper to move in two directions with only one motor. In another commonly used printing device, the laser printer paper is moved with two sets of motors and two sets of cams and paper guides to pass through the printer.
The different printing devices utilize various methods to position a sheet of paper for printing. Some printing devices operate by xe2x80x9ctractor feedxe2x80x9d wherein continuous feed paper is fed through the printing device by way of sprockets. Typically, at least one sprocket is located on each side of the printing device. The sprockets are positioned to correspond with opening in the continuous feed paper. The continuous feed paper is aligned to travel through the printer squarely and only in one direction by positioning the complimentary openings on either side of the continuous paper with complimentary projections in the sprockets.
A method to position separate sheets of paper for printing is by aligning the paper squarely in a paper tray or a holder and using the tangential force imparted by a roller to move a single sheet in position for copying or printing. According to this method, a rotatable roller shaft extends the width of the sheet-feed opening of a printing device. A roller is attached to all or part of the roller shaft. Individual sheets of paper are aligned in a paper tray or a cassette to travel through the printing device squarely through the use of paper guides that correspond to the width and or the length of the individual sheets of paper to be printed. An individual sheet of paper is selected for printing by positioning the sheet in contact with the roller and rotating the roller in a direction to move the paper through the printing device. The individual sheet of paper is positioned in contact with the roller either by force, such as spring tension, or the movement of the paper tray in a direction that will achieve contact with the roller.
Roller driven feed mechanisms use adjustable paper guides to square the paper within a tray so that the paper feeds through the printing device and the printing is formatted correctly on the paper. Additional paper in the paper tray of the roller driven feed mechanism described above encounter problems associated with fanning and skew. Fanning occurs when the paper remaining in the paper tray spreads out and fans toward the printing mechanism causing more than a single sheet of paper to be retrieved by the roller and sent through the printing mechanism. Fanning is a particular problem with those printing devices like the Apple Stylewriter series printers that pivot the paper tray to establish contact between the paper tray and the single sheet of paper. As the paper tray pivots forward and the D-roller selects sheet after sheet of paper, the sheets remaining in the paper tray slowly fan forward and eventually come in contact with or are transported by the D-roller into the printing device.
The present invention is designed to minimize fanning while using fewer parts and a bi-directional movement system, which minimizes the size, needed for the information transport device to which the media transport mechanism is engaged.
There exists a need for an inexpensive information transfer feed device that can provide the functionality of bi-directional feed without the need for two motors, two drivers, two sets of each part.
The invention incorporates bi-directional functionality into a roller driven device for transferring media to an information transfer device without the additional space or expensive requirements associated with bi-directional transfer devices.
According to one aspect of the present invention, an apparatus for transfer media to and from an information transfer device comprises a media tray for holding the media. A drive roller and a first idler roller form a nip for moving the media from the media supply tray to the information transfer device. A drive motor connected to the drive roller rotates the drive roller. A deflector is located between the first nip and the information device. The deflector shifts to a second position to transfer the media from the transfer device to a second nip formed by a second roller and the drive roller. The drive roller, which is in contact with the first and the second roller rotates in only one direction. By moving the deflector between a first and second position the single drive motor and single motor are able to transfer media to and from the information transfer device without reversing the direction of the motor or using a second motor.
The current invention provides an apparatus whereby all stock enters through a single feed port and the invention can utilize the same roller and the same document path for both intake of feed and exit of media containing transferred information. The invention provides the functionality of bi-directional feed in a compact physical space at an inexpensive cost.
The invention can be any information transfer device, such as a scanner, facsimile sending and receiving device, a copier, or a printer.
It is within the scope of the present invention to use different medias in various quantities can be placed in the feed tray.
The invention and its objects and advantages will become more apparent in the detailed description of the preferred embodiment presented below.